Added used-by element, minor css improvements, fixed examples tabs, added project type, fixed bug in tabs across pages

Create vercel proxy for widgets, modify widgets to support proxy

Closes #11 and #13

See merge request cleverthis/fedipage/fedipage!3

Add overview and single version widgets

See merge request cleverthis/fedipage/fedipage!2

Fix mismatched html header tags

Add single version widget

Add empty _index.md